Transparent frozen soil and preparation method and application thereof

ABSTRACT

The present invention discloses a transparent frozen soil, which is prepared from a fluorine-containing polymer, cube ice and a colorless pore fluid by steps of preparing materials, blending, vacuuming, consolidating, and freezing. The fluorine-containing polymer is Teflon AF 1600 produced by American DuPont Company, with the refractive index of 1.31, the particle diameter ≦0.074 mm, and the density of 2.1-2.3 g/cm 3 . The present invention also provides the application of above transparent frozen soil in the frozen soil directional blasting model test and the frozen soil road embankment model thaw-slumping landslide test. The transparent frozen soil prepared by the present invention can well simulate the properties of natural transparent frozen clay, is effectively used in model tests in the geotechnical engineering, with accurate measurement results, and can realize the visualization of the internal deformation of a soil body, and it is low in the expense, and simple in the operation.

TECHNICAL FIELD

The present invention relates to a transparent soil, particularlyrelates to a transparent frozen soil and preparation method andapplication thereof.

BACKGROUND ART

In model tests in the aspect of the geotechnical engineering, thestudies on the internal transformation law and mechanism of soil bodiesare of great significance on the research of the problem inherence ofthe geotechnical engineering. Particularly, the area of perennial frozensoil, seasonal frozen soil and temporary frozen soil regions on earthapproximately accounts for 50% of the land area, wherein thedistribution area of perennial frozen soil is 35,000,000 km²,approximately accounting for 20% of the land area. Frozen soil is a soilbody extremely sensitive to the temperature, along with the rise of thetemperature, its strength obviously reduces, and the strength after thesoil body thaws reduces by a geometry order-of-magnitude relative tothat while in freezing. The results of related studies show that, hillyareas of the abdominal zones of perennial frozen soil regions inQinghai-Tibet Plateau and the like are all possible to form thawslumping on the sloping land greater than 3° in its thawing process.When the surface layer frozen soil thaws due to the rise of theatmospheric temperature, under the condition of high ice content, asliding soil body appears as a mixture of hard rock blocks and liquidslurry, and is easy to generate a sliding plane approximately parallelwith the slope face. For example, in a region between WUdaoliang andTuotuohe near the milestone of the K3035 mileage segment of theQinghai-Tibet highway, with the overall slope of about 7°, a topicalthaw-slumping phenomenon with the longitudinal direction of 95 m and themaximum width of 72 m occurs. Hence, it is important to develop thestudies on the thaw-slumping characteristics and mechanism of low-angleside slopes.

The document “Study on Model Experiment of Thaw Slumping in PermafrostRegion of Qinghai-Tibet Plateau” (Jin Dewu, et al. EngineeringInvestigation, 2006, 9: 1-6) designed a physical model (compressed at ascale of 1:10) similar to the geometry and slope structure of thethaw-slumping body of the K3035 mileage segment of the Qinghai-Tibethighway, and the testing process was divided into several links of icebox processing and ice layer fabrication, soil sample rolling andpreparation; correction and calibration of monitoring instruments,fabrication of a slope scale model in a model box and instrumentembodiment; and a special ice layer was used in the test process for thetemperature control, the temperature was set at −1° C., the other onewas used for controlling the temperature of the soil body, total fourfreezing-thawing periodic cycles were completed, and based onpre-embedded common temperature probes, displacement sensors andextensimeters, the displacement field and the temperature field of theside slop could be measured. However, conventional soil body deformationmeasurement method is to embed a series of sensors inside the soil body,and obtain the displacements of some discrete points, the sensors areeasily subjected to the effect due to the disturbance of the externalenvironment, the measurement result often are not accurate, and thewhole displacement field in continuous deformation inside the soil bodycan not be presented as well. Modern digital image technologies are onlylimited to measure the macroscopic or boundary deformation of the soilbody as well, and can not realize the visualization of the internaldeformation of the soil body; and although X-ray, γ-ray, computerassisted tomographic scanning (CAT scanning) and magnetic resonanceimaging technology (MRI) can be used for measuring the continuousdeformation inside the soil body, and expensive expenses limit wideapplication of these technologies.

Controlled blasting is a blasting technique, which controls publichazards of frying objects, earthquake, air shock wave, fume, noise andso on generated due to the explosion of an object to be blasted byexplosive by certain technical means, and has wide application in theengineering construction, for example, directional blasting,presplitting blasting, smooth surface blasting, rock plug blasting,millisecond controlled blasting; demolition blasting, static blasting,casting-filling blasting, weakly loose blasting, combustion agentblasting and the like. The directional blasting is a blasting technique,which utilizes the explosion action of explosive, to throw earth andstone of a certain region to a specified region and approximately stackinto a required shape, is mainly used for repairing dams (water dams ortailing dams), building roads (road embankments and roadbeds), andleveling land (industrial lands and farmland construction), and isparticularly suitable for work points of labor shortage, inconvenienttransportation and no construction yard.

Document 1 “Study on Frozen Soil Blasting Crater and Model Test OfFrozen Soil Blastability” (Ma Qinyong. Journal of China Coal Society,1997, 22(3): 288-293) disclosed a program for the blasting crater modeltests of frozen clay and sand soil at different temperatures; document 2“Preliminary Study on Blasting Parameters for Shaft Excavation in FrozenSoil” (Zong Qi, Yang Lujun, Engineering blasting, 1999, 5(2): 25-29),and document 3 “Study of Smooth Blasting in Frozen Soil of the Shaft bySimulation” (Jiang Yusong, Journal of Huainan Institute of Technology)(2001, 21(4): 31-34) disclosed a program for cutting blasting and smoothblasting model tests of frozen sand soil; and Document 4 “A Study onBlasting Tests and Methods for Permafrost and Artificially Frozen Soils”(Ma Qinyong, Journal of Civil Engineering, 2004, 37(9): 75-78)comprehensively introduced the research developments and achievements ofblasting craters, cutting blasting and smooth blasting tests of frozensoil. These model test programs are all based on conventional testmeans, and are incapable of effectively acquiring specific fracturemorphologies of frozen soil after the blasting tests. However,conventional soil body deformation measurement method is to embed aseries of sensors inside the soil body, and obtain the displacements ofsome discrete points, the sensors are easily subjected to the effect dueto the disturbance of the external environment, the measurement resultoften are not accurate, and the whole displacement field in continuousdeformation inside the soil body can not be presented as well. Moderndigital image technologies are only limited to measure the macroscopicor boundary deformation of the soil body as well, and can not realizethe visualization of the internal deformation of the soil body; andalthough X-ray, γ-ray, computer assisted tomographic scanning (CATscanning) and magnetic resonance imaging technology (MRI) can be usedfor measuring the continuous deformation inside the soil body, andexpensive expenses limit wide application of these technologies.

Artificial synthesis of transparent soil in combination with opticalobservation and image processing techniques is utilized to realize thevisualization of the internal deformation of the soil body, with lowexpense, and simple operation, and can be widely applied in model testsin the aspect of the geotechnical engineering, to study the internal lawand mechanism of the soil body, which is of great significance on theresearch of the problem inherence of the geotechnical engineering. Itsprecondition is to obtain an artificially synthesized transparent soilwith high transparency, and the properties similar to natural soil body.At present, different materials were adopted to prepare transparentsoil, and some achievements were obtained. However, existing technicaldata show that, solid particles for preparing transparent soil mainlyadopt quartz materials, with the refractive index themselves of thesolid particles between 1.44-1.46, and adopt borosilicate glassmaterials, with the refractive index themselves of the solid particlesbetween 1.46-1.48, which is far higher than the refractive index ofwater of 1.33 and that of ice of 1.31. Hence, the utilization ofexisting solid particles for preparing transparent soil is incapable ofpreparing a saturated transparent frozen soil sample.

The fluorine-containing polymer is Teflon AF 1600 produced by AmericanDuPont Company, with the refractive index of 1.31, and the density of2.1-2.3 g/cm³; and it has the characteristics of high temperatureresistance, low temperature resistance, chemical corrosion resistance,no viscosity, no toxicity, no pollution, high transparency and lowrefractive index, and also has the characteristics of gas permeabilitystructure, hydrophobicity and chemical inertness, and has goodsimilarity with the properties of natural soil body. Teflon AF 1600 canbe dissolved in fluorine solvents, and can be formed into a film orformed by fusion compression; and at present, it is mainly used incoating and impregnation or made into fibers, and the prepared liquidcore also has application in various fields of absorption, fluorescence,Raman spectral analysis, gas sensors and the like. Thefluorine-containing polymer has high transparency, and the refractiveindex the same as ice, thus can be used as a transparent solid materialin the preparation of transparent frozen soil.

SUMMARY OF THE INVENTION

The objective of the invention: in order to solve technical problemsexisting in the prior art, the present invention provides a transparentfrozen soil and preparation method and application thereof, and theprepared transparent frozen soil can well simulate the properties ofnatural transparent frozen clay.

The technical content: in order to realize above technical objective,the present invention provides a transparent frozen soil, characterizedin that it is prepared from a fluorine-containing polymer, cube ice anda colorless pore liquid by steps of preparing materials, blending,vacuuming, consolidating, and freezing, and the dosages of saidfluorine-containing polymer, cube ice and colorless pore fluid arecalculated by test conditions and sample sizes; said colorless porefluid is water, said fluorine-containing polymer is particles with theparticle diameter ≦0.074 mm, and its particles have irregular shape, andare Teflon AF 1600 produced by American DuPont Company, with therefractive index of 1.31, and the density of 2.1-2.3 g/cm³; the particlediameter of said cube ice is ≦0.074 mm; the physical properties of saidtransparent frozen soil are: density of 1.63-2.1 g/cm³, unit weight of15-20 k N/m³, and over-consolidation ratio OCR value of 0.8-3; and themechanical properties are: internal friction angle of 19°-22°, cohesionof 1-3 kPa, elasticity modulus of 5-9 MPa, and Poisson's ratio of0.2-0.3.

In order to reduce the effect on the refractive index, said water ispurified water.

The invention also provides a production method for above transparentfrozen soil, characterized in that it includes the following steps:

(1) material preparation: the dosages of the fluorine-containingpolymer, the cube ice and the colorless pore fluid are calculatedaccording to the test conditions and sample size dimensions; saidfluorine-containing polymer is particles with the particle diameter≦0.074 mm, and is subjected to impurity cleaning and oven dried, and itsparticles have irregular shape, and are Teflon AF 1600 produced byAmerican DuPont Company, with the refractive index of 1.31, and thedensity of 2.1-2.3 g/cm³; said cube ice is obtained by mashing a frozenwhole ice block, with the particle diameter ≦0.074 mm; and saidcolorless pore fluid is water.

(2) blending: in a −6.0° C. to −8.0° C. cryogenics laboratory, firstlythe fluorine-containing polymer and the cube ice are stirred uniformly,and loaded into a mold by 2-3 batches for the preparation of a sample,and compacted layer by layer; then water is added into the mold, andfills gaps between the fluorine-containing polymer particles and thecube ice;

(3) vacuuming: a vacuuming device is utilized to remove bubbles residualinside the sample, so that the sample reaches a fully saturated state;and

(4) consolidating: placing the sample in a consolidometer, with theover-consolidation ratio OCR value of 0.8-3; and

(5) freezing: the sample is loaded in a −20° C. cryogenic box and frozenfor 48 h, so as to prepare a transparent frozen soil simulatingsaturated frozen clay, the physical properties of which are: density of1.63-2.1 g/cm³, unit weight of 16-21 kN/m³, and the over-consolidationratio OCR value of 0.8-3; and the mechanical properties are: internalfriction angle of 19°-22°, cohesion of 1-3 kPa, elasticity modulus of5-9 MPa, and Poisson's ratio of 0.2-0.3.

In step (1), said water is purified water.

The present invention further provides application of above transparentfrozen soil in the frozen soil directional blasting model test.

The above application comprises the following processes:

(1) modeling: according to the test requirements and the natural frozensoil side slope model dimensions, a transparent model tank and atransparent frozen soil side slope model simulating the natural frozensoil side slope model are made, respectively, and said transparentfrozen soil side slope model is made of transparent frozen soil, andreserved with blast holes; and said transparent model tank is made oftransparent toughened glass;

(2) mounting; the transparent frozen soil side slope model is loadedinto the transparent model tank, and according to the test design,detonators and explosive are loaded in the reserved blast holes; anddigital cameras capable of observing the space of the whole transparentmodel tank are arranged on the front view face, the side view face andthe top view face outside the transparent model tank, and the digitalcameras are connected with a processing device via data lines;

(3) testing: the detonators and explosive are detonated, the process ofthe directional blasting of the transparent frozen soil side slope modelto form an artificial side slope is observed and recorded by the digitalcameras, and the recorded data are sent to the processing device by datalines; and

(4) process (1)-process (3) are repeated, the directional blastingprocesses of the transparent frozen soil side slope model under theconditions of different natural side slop heights, different blast holediameters and depths and different explosive dosages can be observed bythe processing device, so as to analyze the frozen soil directionalblasting mechanism, and complete the directional blasting test of thefrozen soil side slop model.

The present invention more further provides application of the abovetransparent frozen soil in the frozen soil road embankment modelthawing-slumping test.

(1) modeling: according to the test requirements and frozen soil roadembankment model dimensions a transparent model tank and a transparentfrozen soil road embankment model simulating a frozen soil roadembankment model are made, respectively, and said transparent frozensoil road embankment model is made of the transparent frozen soilmaterial, and pre-embedded with temperature sensors; and saidtransparent model tank is made of organic glass;

(2) mounting; in a cryogenic laboratory, the transparent frozen soilroad embankment model is loaded into the transparent model tank, and aheating source is mounted on the transparent model tank, and above theadret face of the transparent frozen soil road embankment model; outsidethe transparent model tank, one side parallel to the cross section ofthe transparent frozen soil road embankment model is provided with alaser source, and one side perpendicular to the cross section of thetransparent frozen soil road embankment model is provided with a digitalcamera, and the digital camera and the temperature sensor are connectedwith the processing device via data lines; and the axial line of saiddigital camera is perpendicular to that of said laser source, and theintersection point of the axial line of said digital camera and that ofsaid laser source is located inside said transparent model tank; and

(3) testing: the laser source is turned on, the brightness of thetangent plane of particles formed inside the transparent frozen soilroad embankment model is inspected, and the laser angle is adjusted, sothat the laser is perpendicularly incident onto the tangent plane, andthrough the middle position of the longitudinal direction of thetransparent frozen soil road embankment model; the digital camera isturned on, and the lens of the digital camera is adjusted, so that itcan cover the adret face and the ubac face of the transparent frozensoil road embankment model; i.e. the laser source irradiates the crosssection of the transparent frozen soil road embankment model, and thecross section of the transparent frozen soil road embankment modelirradiated by the laser source is recorded by the digital camera; andaccording to the experiment design, the heating source is intermittentlyturned on, the thawing-slumping process of the adret face of thetransparent frozen soil road embankment model under the periodic cycleof freezing and thawing is observed and recorded by the digital camera,and the recorded data are sent to the processing device via a data line.

Preferably, in step (2), the adret face is laid with thereon a thermalinsulating material, and the toe position of the adret face is providedwith a bridge wall; said thermal insulating material is a broken stonelayer simulated by fluorine-containing polymer particles with thethickness of 5-15 mm or a polyethylene foamed plastic mesh, and saidretaining wall is made of organic glass; and in step (3), according tothe experiment design, the heating source is intermittently turned on,the thawing-slumping process of the adret face of the transparent frozensoil road embankment model under the periodic cycle of freezing andthawing is observed and recorded by the digital camera, the recordeddata are sent to the processing device via a data line, and the effectof treatment measures on the elimination of the thawing-slumpingphenomenon is examined.

The beneficial effect: compared with the prior art, the presentinvention adopts fluorine-containing polymer Teflon AF 1600 with therefractive index the same as ice, cube ice and water to prepare atransparent frozen soil, the prepared one has good similarity with theproperties of the natural frozen soil body, can widely substitutenatural frozen coil, well simulates the properties of naturaltransparent frozen clay, is effectively used in model tests in thegeotechnical engineering, including the simulation of frozen soildirectional blasting and thaw slumping, with accurate measurementresults, and can realize the visualization of the internal deformationof a soil body, and it is low in the expense, and simple in theoperation.

DESCRIPTION OF DRAWINGS

FIG. 1 A schematic diagram of a frozen soil side slope model directionalblasting test device; and

FIG. 2 A schematic diagram of a frozen soil road embankment modelthaw-slumping test device.

PARTICULAR EMBODIMENTS Example 1 Preparation of Transparent Frozen Soil

Application of a fluorine-containing polymer in the preparation of atransparent frozen soil: it is used as a transparent solid materialwhile in the preparation of a transparent frozen soil, saidfluorine-containing polymer is particles with the particle diameter≦0.074 mm, and its particles have irregular shape, and are Teflon AF1600 produced by American DuPont Company, with the refractive index of1.31, and the density of 2.1-2.3 g/cm³.

A production method for the preparation of a transparent frozen soilfrom the above fluorine-containing polymer comprises the followingsteps:

(1) material preparation: the dosages of the fluorine-containingpolymer, the cube ice and the colorless pore fluid are calculatedaccording to the test conditions and the sample size dimensions; saidfluorine-containing polymer is particles with the particle diameter≦0.074 mm, and is subjected to impurity cleaning and oven dried, and itsparticles have irregular shape, and are Teflon AF 1600 produced byAmerican DuPont Company, with the refractive index of 1.31, and thedensity of 2.1-2.3 g/cm³; said cube ice is obtained by mashing a frozenwhole ice block, with the particle diameter ≦0.074 mm; the colorlesspore fluid is water; and in order not to affect the refractive index, instep (1) of the present invention, said water is purified water;

the dosages of the fluorine-containing polymer, the cube ice and thecolorless pore fluid are determined according to the test conditions andthe sample size dimensions;

the sample of the example has the water content of 100.0%, the drydensity of 0.55 g/cm³, and the sample size (height of 125.0 mm anddiameter of 61.8 mm), the temperature of the cryogenic laboratory is of−6.0° C., the mass of the fluorine-containing polymer particles (themass of particles=dry density×sample volume) required for preparing asample is calculated to be 206.0 g, and the total water content (watercontent of 100.0%, and the mass of the total water content is equal tothe mass of particles) is 206.0 g; and since clay has the non-frozenwater content about 15% when the temperature is at −6.0° C., the mass ofpurified water added in the preparation process of the sample should be30.9 g, and the mass of the cube ice is 175.1 g;

(2) blending: in the −6.0° C. to −8° C. cryogenic laboratory, firstlythe fluorine-containing polymer particles and the cube ice determined instep (1) are stirred uniformly, loaded into a mold by 2-3 batches forthe preparation of a sample, and compacted layer by layer; then water isadded into the mold, and fills the gaps between the fluorine-containingpolymer particles and the cube ice;

in the example, in the −6.0° C. cryogenics laboratory, firstly thefluorine-containing polymer particles and the cube ice determined instep (1) are stirred uniformly, loaded into a mold by 3 batches for thepreparation of a sample, and compacted layer by layer, to a designedrelative density; then purified water is added into the mold, and fillsgaps between the fluorine-containing polymer particles and the cube ice;

(3) vacuuming: a vacuuming device is utilized to remove bubbles residualinside the sample, so that the sample reaches a fully saturated state;and

(4) consolidating: placing the sample in a consolidometer forconsolidation, with the over-consolidation ratio OCR value of 0.8-3; and

the over-consolidation ratio OCR value of the example is 1.5; and

(5) freezing: the sample is loaded in a −20° C. cryogenic box and frozenfor 48 h, so as to prepare a transparent frozen soil simulatingsaturated frozen clay, the physical properties of which are: density of1.93 g/cm³, and unit weight of 19.1 kN/m³; and the mechanical propertiesare: internal friction angle of 20°, cohesion of 3 kPa, elasticitymodulus of 9 MPa, and Poisson's ratio of 0.3.

Said transparent frozen soil of the example can be used for simulatingsaturated frozen clay.

Example 2 Preparation of Transparent Frozen Soil

The preparation steps are the same as those of the example 1, and thedifference is, in step (1), fluorine-containing polymer particles of thedensity of 2.1 g/cm³ are selected;

in step (4), the over-consolidation ratio OCR value is 0.8; and

the physical properties of the transparent frozen soil prepared by theexample are: density of 1.83 g/cm³, and unit weight of 18 kN/m³; and themechanical properties are: internal friction angle of 19°, cohesion of 1kPa, elasticity modulus of 5.2 MPa, and Poisson's ratio of 0.22.

Said transparent frozen soil of the example can be used for simulatingsaturated frozen clay. Example 3 Application of application of thetransparent frozen soil in the frozen soil directional blasting modeltest. A frozen soil side slope directional blasting test device,comprises the transparent model tank 1-1, the transparent model tank 1-1is provided with therein the transparent frozen soil side slope model1-2 simulating the natural side slope 1-4, the transparent frozen soilside slope model 1-2 is sequentially provided with therein blast holes1-3, and the blast holes 1-3 are provided with therein explosive anddetonators; the digital cameras 1-6 capable of observing the space ofthe whole transparent model tank 1-1 are arranged on the front viewface, the side view face and the top view face outside the transparentmodel tank 1-1, and the digital cameras 1-6 are connected with aprocessing device 1-7 via data lines; and while in the directionalblasting, the process of the directional blasting of the transparentfrozen soil side slope model 1-2 to form the artificial side slope 1-5under the conditions of different natural side slop 1-4 heights,different blast hole diameters and depths and different explosivedosages is observed by the digital cameras 1-6, and the recorded dataare sent to the processing device 1-7, so as to complete the directionalblasting test of the frozen soil side slop model. Said transparent modeltank 1-1 of the present invention is made of transparent toughenedglass.

Said transparent frozen soil side slope model 1-2 of the presentinvention is made of the transparent frozen soil material prepared bythe example 1 and example 2 in a transparent model tank with therequired dimensions. Said digital cameras 1-6 of the present inventionare high-resolution high-speed digital cameras, with the resolution of50-500 w (500 w is adopted in the present invention), frame exposure,the frame number of 25, and the exposure time of 10 μs-10 s (10 μs isadopted in the present invention). The frozen soil side slope modeldirectional blasting test method comprises the following processes: (1)modeling: according to the test requirement and the natural frozen soilside slope model dimensions, the transparent model tank 1-1 and thetransparent frozen soil side slope model 1-2 simulating the naturalfrozen soil side slope model are made, respectively, said transparentfrozen soil side slope model 1-2 is made of transparent frozen soil, andreserved with blast holes 1-3; and said transparent model tank 1-1 ismade of transparent toughened glass; and firstly a mold simulating thenatural side slope model is fabricated according to the testrequirements, and the dosages of the fluorine-containing polymer, thecube ice and the colorless pore fluid are calculated according to thetest conditions and mold size dimensions; and the example adopts thepreparation of example 1 to prepare a transparent frozen soil in themold, to obtain the transparent frozen soil side slope model 1-2simulating the natural frozen soil side slope model; (2) mounting; thetransparent frozen soil side slope model 1-2 is loaded into thetransparent model tank 1-1, and according to the test design, detonatorsand explosive are loaded in the reserved blast holes 1-3, and the dosageof the explosive is determined according to the test design; digitalcameras 1-6 capable of observing the space of the whole transparentmodel tank 1-1 are arranged on the front view face, the side view faceand the top view face outside the transparent model tank 1-1, and thedigital cameras 1-6 are connected with a processing device 1-7 via datalines; and said digital cameras 1-6 of the present invention arehigh-resolution high-speed digital cameras, with the resolution of 500w, frame exposure, frame number of 25, and exposure time of 10 μs; (3)testing: the detonators and explosive are detonated, the process of thedirectional blasting of the transparent frozen soil side slope model 1-2to form an artificial side slope is observed and recorded by the digitalcameras 1-6, and the recorded data are sent to the processing device 1-7by data line; and In the test, the PIV technology (Particle ImageVelocimetry) in combination with image process software PIVview2C isutilized to process the picture data acquired by the numeral cameras1-6; and (4) process (1)-process (3) are repeated, the directionalblasting processes of the transparent frozen soil side slope model 1-2under the conditions of different natural side slop 1-4 heights,different blast hole 1-3 diameters and depths and different explosivedosages can be observed by the processing device 1-7, so as to analyzethe frozen soil directional blasting mechanism, and complete thedirectional blasting test of the frozen soil side slop model 1-2.Example 4 Application of the transparent frozen soil in the frozen soilroad embankment model thawing-slumping test. A frozen soil roadembankment thaw-slumping test device, comprises the cryogenic laboratory2-1, the cryogenic laboratory 2-1 is provided with therein thetransparent model tank 2-5, the transparent model tank 2-5 is providedwith therein the transparent frozen soil road embankment model 2-13simulating the road embankment 2-9, the transparent frozen soil roadembankment model 2-13 is pre-embedded with therein a temperature sensor2-12, and the adret face of the road embankment 2-9 is provided withthereabove the heating source 2-6 mounted on the transparent model tank2-5; the adret face 2-7 is laid with thereon the thermal insulatingmaterial 2-11, and the toe position of the adret face 2-7 is providedwith the bridge wall 2-10; outside the transparent model tank 2-5, oneside parallel to the cross section of the transparent frozen soil roadembankment model 2-13 is provided with the laser source 2-2 (disposed atone side of the ubac face 2-8 in the example), and one sideperpendicular to the cross section of the transparent frozen soil roadembankment model 2-13 is provided with the digital camera 2-3, and thedigital camera 2-3 and the temperature sensor 2-12 are connected withthe processing device 2-4 via a data line; the axial line of saiddigital camera 2-3 is perpendicular to that of said laser source 2-2,and the intersection point of the axial line of said digital camera 2-3and that of said laser source 2-2 is located inside said transparentmodel tank 2-5; and the laser source 2-2 irradiates the cross section ofthe transparent frozen soil road embankment model 2-13, and the crosssection of the transparent frozen soil road embankment model 2-13irradiated by the laser source 2-2 is recorded by the digital camera2-3.

Said transparent frozen soil road embankment model 2-13 of the presentinvention is made of the transparent frozen soil, the dosages of thefluorine-containing polymer, the cube ice and purified water arecalculated according to the test conditions and the sample sizedimensions in the mold, and the transparent frozen soil road embankmentmodel 2-13 is prepared in the mold by adopting the method of the example2 for preparing the transparent frozen soil. When the slope angles ofthe adret face 2-7 and the ubac face 2-8 are greater than 4°-9°, thepossibility of the occurrence of thaw slumping exists. The slope angleof the adret face 2-7 of the transparent frozen soil road embankmentmodel 2-13 prepared by the example is 31°, and that of the ubac face 2-8is 36°. Said transparent model tank 2-5 and the bridge wall 2-10 of thepresent invention are made of organic glass; and said thermal insulatingmaterial 2-11 is a broken stone layer simulated by fluorine-containingpolymer particles with the thickness of 5-15 mm or a polyethylene foamedplastic mesh. Said heating source 2-6 of the present invention is alinear heating resistance wire, and the maximum temperature near theresistance wire can be up to 25-28° C. Said laser source 2-2 of thepresent invention is an intracavity-type helium-neon laser device, andthe power can be 50-500 mW (500 mW in the example).

Said digital cameras 1-6 of the present invention are high-resolutionhigh-speed digital cameras, with the resolution of 50-500 w (500 w inthe example), frame exposure, frame number of 25, and exposure time of10 μs-10 s (10 μs in the example). Particularly, the frozen soil roadembankment model thaw-slumping test method comprises the followingprocesses: (1) modeling: the transparent model tank 2-5 and thetransparent frozen soil road embankment model 2-3 simulating the frozensoil road embankment model are made, respectively according to the testrequirement and frozen soil road embankment model dimensions, saidtransparent frozen soil road embankment model 2-13 is made of thetransparent frozen soil material, and pre-embedded with the temperaturesensor 2-12; and said transparent model tank 2-5 is made of organicglass; (2) mounting; in the cryogenic laboratory 2-1, the transparentfrozen soil road embankment model 2-13 is loaded into the transparentmodel tank 2-5, and the heating source 2-6 is mounted on the transparentmodel tank 2-5, and above the adret face 2-7 of the transparent frozensoil road embankment model 2-13; outside the transparent model tank 2-5,one side parallel to the cross section of the transparent frozen soilroad embankment model 2-13 is provided with the laser source 2-2(disposed at one side of the ubac face 2-8 in the example), and one sideperpendicular to the cross section of the transparent frozen soil roadembankment model 2-13 is provided with the digital camera 2-3, and thedigital camera 2-3 and the temperature sensor 2-12 are connected withthe processing device 2-4; the axial line of said digital camera 2-3 isperpendicular to that of said laser source 2-2, and the intersectionpoint of the axial line of said digital camera 2-3 and that of saidlaser source 2-2 is located inside said transparent model tank 2-5; andsaid heating source 2-6 of the present invention is a linear heatingresistance wire, and the maximum temperature near the resistance wirecan be up to 25-28° C. Said laser source 2-2 of the present invention isan intracavity-type helium-neon laser device, and the power can be50-500 mW (500 m W in the example). Said digital cameras 1-6 of thepresent invention are high-resolution high-speed digital cameras, withthe resolution of 50-500 w (500 w in the example), frame exposure, framenumber of 25, and exposure time of 10 μs-10 s (10 μs in the example).(3) testing: the laser source 2-2 is turned on, the brightness of thetangent plane of particles formed inside the transparent frozen soilroad embankment model 2-13 is inspected, and the laser angle isadjusted, so that the laser is perpendicularly incident onto the tangentplane, and through the middle position of the longitudinal direction ofthe transparent frozen soil road embankment model 2-13; the digitalcamera 2-3 is turned on, and the lens of the digital camera 2-3 isadjusted, so that it can cover the adret face 2-7 and the ubac face 2-8of the transparent frozen soil road embankment model 2-13; i.e. thelaser source 2-2 irradiates the cross section of the transparent frozensoil road embankment model 2-13, and the cross section of thetransparent frozen soil road embankment model 2-13 irradiated by thelaser source is recorded by the digital camera 2-3; and according to theexperiment design, the heating source 2-6 is intermittently turned on,the thawing-slumping process of the adret face 2-7 of the transparentfrozen soil road embankment model 2-13 under the periodic cycle offreezing and thawing is observed and recorded by the digital camera 2-3,and the recorded data are sent to the processing device 2-4 via a dataline. In the test, the PIV technology (Particle Image Velocimetry) incombination with image process software PIVview2C is utilized to processthe picture data acquired by the numeral cameras 1-6; and in order toexamine the effect of treatment measures on the elimination of thethaw-slumping phenomenon, the adret face is laid with therein thethermal insulating material 2-11, and the toe position of the adret faceis provided with the bridge wall 2-10; said thermal insulating material2-11 is a broken stone layer simulated by fluorine-containing polymerparticles with the thickness of 5-15 mm or a polyethylene foamed plasticmesh (a broken stone layer simulated by fluorine-containing polymerparticles with the thickness of 10 mm in the example), and saidretaining wall is made of organic glass; and in step (3), according tothe experiment design, the heating source 2-6 is intermittently turnedon, the thawing-slumping process of the adret face 2-7 of thetransparent frozen soil road embankment model 2-13 under the periodiccycle of freezing and thawing is observed and recorded by the digitalcamera 2-3, the recorded data are sent to the processing device 2-4 viaa data line, and the effect of treatment measures on the elimination ofthe thawing-slumping phenomenon is examined.

1. A transparent frozen soil, characterized in that it is prepared froma fluorine-containing polymer, cube ice and a colorless pore fluid bysteps of preparing materials, blending, vacuuming, consolidating, andfreezing, and the dosages of said fluorine-containing polymer, cube iceand colorless pore fluid are calculated by the test conditions and thesample sizes; said colorless pore fluid is water, saidfluorine-containing polymer is particles with the particle diameter≦0.074 mm, and its particles have irregular shape, and are Teflon AF1600 produced by American DuPont Company, with the refractive index of1.31, and the density of 2.1-2.3 g/cm³; the particle diameter of saidcube ice is ≦0.074 mm; the physical properties of said transparentfrozen soil are: density of 1.63-2.1 g/cm³, unit weight of 16-21 kN/m³,and over-consolidation ratio OCR value of 0.8-3; and the mechanicalproperties are: internal friction angle of 19°-22°, cohesion of 1-3 kPa,modulus of 5-9 MPa, and Poisson's ratio of 0.2-0.3.
 2. The transparentfrozen soil according to claim 1, characterized in that said water ispurified water.
 3. A production method for the transparent frozen soilaccording to claim 1, characterized in that it includes the followingsteps: (1) material preparation: the dosages of the fluorine-containingpolymer, the cube ice and the colorless pore fluid are calculatedaccording to the test conditions and the sample size dimensions; saidfluorine-containing polymer is particles with the particle diameter≦0.074 mm, and is subjected to impurity cleaning and oven dried, and itsparticles have irregular shape, and are Teflon AF 1600 produced byAmerican DuPont Company, with the refractive index of 1.31, and thedensity of 2.1-2.3 g/cm³; said cube ice is obtained by mashing a frozenwhole ice block, with the particle diameter ≦0.074 mm; and saidcolorless pore liquid is water; (2) blending: in a −6.0° C. to −8.0° C.cryogenics laboratory, firstly the fluorine-containing polymer and thecube ice are stirred uniformly, and loaded into a mold by 2-3 batchesfor the preparation of a sample, and compacted layer by layer; thenwater is added into the mold, and fills gaps between thefluorine-containing polymer particles and the cube ice; (3) vacuuming: avacuuming device is utilized to remove bubbles residual inside thesample, so that the sample reaches a fully saturated state; (4)consolidating: placing the sample in a consolidometer for consolidation,with the over-consolidation ratio OCR value of 0.8-3; and (5) freezing:the sample is loaded in a −20° C. cryogenic box for freezing for 48 h,so as to prepare a transparent frozen soil simulating saturated frozenclay, the physical properties of which are: density of 1.63-2.1 g/cm³,unit weight of 16-21 kN/m³, and over-consolidation ratioover-consolidation ratio OCR value of 0.8-3; and the mechanicalproperties are: internal friction angle of 19°-22°, cohesion of 1-3 kPa,modulus of 5-9 MPa, and Poisson's ratio of 0.2-0.3.
 4. The productionmethod of said transparent frozen soil according to claim 3,characterized in that in step (1), said water is purified water. 5.Application of said transparent frozen soil according to claim 1 in thefrozen soil directional blasting model test.
 6. The applicationaccording to claim 5, characterized by includes the following processes:(1) modeling: according to the test requirements and the natural frozensoil side slope model dimensions, a transparent model tank and atransparent frozen soil side slope model simulating the natural frozensoil side slope model are made, respectively, said transparent frozensoil side slope model is made of transparent frozen soil, and reservedwith blast holes; and said transparent model tank is made of transparenttoughened glass; (2) mounting; the transparent frozen soil side slopemodel is loaded into the transparent model tank, and according to thetest design, detonators and explosive are loaded in the reserved blastholes; and digital cameras capable of observing the space of the wholetransparent model tank are arranged on the front view face, the sideview face and the top view face outside the transparent model tank, andthe digital cameras are connected with a processing device via datalines; (3) testing: the detonators and explosive are detonated, theprocess of the directional blasting of the transparent frozen soil sideslope model to form an artificial side slope is observed and recorded bythe digital cameras, and the recorded data are sent to the processingdevice by data lines; and (4) process (1)-process (3) are repeated, thedirectional blasting processes of the transparent frozen soil side slopemodel under the conditions of different natural side slop heights,different blast hole diameters and depths and different explosivedosages can be observed by the processing device, so as to analyze thedirectional blasting mechanism of the frozen soil, and complete thedirectional blasting test of the frozen soil side slop model. 7.Application of transparent frozen soil according to claim 1 in thefrozen soil road embankment model thawing-slumping test.
 8. Theapplication according to claim 7, characterized by comprising thefollowing steps: (1) modeling: according to the test requirements andfrozen soil road embankment model dimensions the transparent model tankand the transparent frozen soil road embankment model simulating thefrozen soil road embankment model are made, respectively, saidtransparent frozen soil road embankment model is made of the transparentfrozen soil material, and pre-embedded with temperature sensors; andsaid transparent model tank is made of organic glass; (2) mounting; in acryogenic laboratory, the transparent frozen soil road embankment modelis loaded into the transparent model tank, and a heating source ismounted on the transparent model tank, and above the adret face of thetransparent frozen soil road embankment model; outside the transparentmodel tank, one side parallel to the cross section of the transparentfrozen soil road embankment model is provided with a laser source, andone side perpendicular to the cross section of the transparent frozensoil road embankment model is provided with a digital camera, and thedigital camera and the temperature sensor are connected with theprocessing device via a data line; and the axial line of said digitalcamera is perpendicular to that of said laser source, and theintersection point of the axial line of said digital camera and that ofsaid laser source is located inside said transparent model tank; and (3)testing: the laser source is turned on, the brightness of the tangentplane of particles formed inside the transparent frozen soil roadembankment model is inspected, and the laser angle is adjusted, so thatthe laser is perpendicularly incident onto the tangent plane, andthrough the middle position of the longitudinal direction of thetransparent frozen soil road embankment model; the digital camera isturned on, and the lens of the digital cameras is adjusted, so that itcan cover the adret face and the ubac face of the transparent frozensoil road embankment model; i.e. the laser source irradiates the crosssection of the transparent frozen soil road embankment model, and thecross section of the transparent frozen soil road embankment modelirradiated by the laser source is recorded by the digital camera; andaccording to the experiment design, the heating source is intermittentlyturned on, the thawing-slumping process of the adret face of thetransparent frozen soil road embankment model under the periodic cycleof freezing and thawing is observed and recorded by the digital cameras,and the recorded data are sent to the processing device via a data line.9. The application according to claim 8, characterized in that in step(2), the adret face is laid with thereon a thermal insulating material,and the toe position of the adret face is provided with a bridge wall;said thermal insulating material is a broken stone layer simulated byfluorine-containing polymer particles with the thickness of 5-15 mm or apolyethylene foamed plastic mesh, and said bridge wall is made oforganic glass; and in step (3), according to the experiment design, theheating source is intermittently turned on, the thawing-slumping processof the adret face of the transparent frozen soil road embankment modelunder the periodic cycle of freezing and thawing is observed andrecorded by the digital cameras, the recorded data are sent to theprocessing device via a data line, and the effect of treatment measureson the elimination of the thawing-slumping phenomenon is examined.